Update staking precompile for rao

[gztensor]

Staking precompile is implemented here: https://github.com/opentensor/subtensor/blob/feat/evm-devnet-ready/runtime/src/precompiles/staking.rs https://github.com/opentensor/subtensor/blob/feat/evm-devnet-ready/runtime/src/precompiles/solidity/staking.sol https://github.com/opentensor/subtensor/blob/feat/evm-devnet-ready/runtime/src/precompiles/solidity/staking.abi

There are two things that need to happen for compatibility with rao:

• [ ] Right away: Update interface of add_stake and remove_stake methods so that it can accept netuid parameter and only accept root ID for now. Revert if netuid is not root.
• [ ] After rao is out: Respect netuid parameter and stake to the corresponding netuid.